The present invention relates to a lens for collecting solar rays or artificial light rays having light rays' component near to that of the solar rays, in particular, relates to a lens capable of effectively separating and focusing only the light component of a desired wave length among the solar rays' components or the artificial light rays' components.
The present applicant has previously proposed various ways to focus solar rays or artificial light rays by use of lenses or the like, to guide the same into an optical conductor, and thereby to transmit them onto an optional desired place through the optical conductor for use in illumination or for other like purposes.
However, in the case of employing the light energy transmitted through the optical conductor in such a manner as mentioned above as a photo-synthesis light source for nurturing chlorella or intensively cultivate the plants, a light source for breeding fish, a light source for promoting human health, and a light source utilized for various other purposes, there are many cases in which only a desired light component fitted in the purpose of utilization needs to be selectively separated and employed among the light components contained in the light energies.
However, although various techniques of cutting off infrared rays, ultraviolet rays, or the like have already been proposed up to now, a technique of taking out a light component of the specially designated wave length among the white light rays has not yet been proposed at all. Furthermore, it was very difficult to obtain the infrared rays, the ultraviolet rays, or the like which contain no visible light rays' component or very small amount of component of those visible rays.